Publications

Analyzing thin bed reservoir requires more-accurate and higher-resolution logging tools. Standard open-hole logs are incapable of analyzing the vertical resolution of thin bed layers. The high vertical resolution borehole imaging tool supported with standard logs generate more accurate and detailed estimation of thin bed computation. This technique is developed to derive a better quantitative analysis, including net-pay, porosity and water saturation calculation. An Indonesian operator faced non optimal standard log formation evaluation compared with mud log and drilling data. By recognizing that problem, an integrated solution was posed to analyze the thin bed and to optimize water saturation calculation. Normally, thin bed analysis is performed by using high-resolution resistivity data from wireline log, but recently an approach to performing thin bed analysis has emerged that uses an LWD resistivity image taken during drilling. The LWD image with 1inch vertical resolution is sufficient enough to accurately analyze thin beds compared to only using standard logs. The LWD tool produces absolute formation resistivity and is comparable with standard open-hole resistivity but with higher vertical resolution. Thin beds orientation (azimuth and dip) and determination were obtained from manual dip interpretation using resistivity image data. Hence allow this analysis to also provide a true vertical thickness calibration. Sand count is then calculated with possible cutoffs and corresponds into lithology. Schlumberger internal petrophysical techniques known as SHARP, utilizes high-resolution resistivity log from image that enhance the vertical resolution of standard log and to perform more-accurate thin bed petrophysical evaluation, which output very-high-resolution squared log, formation evaluation and thin bed reservoir summation. The Sand-count and SHARP analysis results are then compared to validate and optimize the method for thin bed identification and property determination. These analyses were implemented in GB wells and provide an improvement and accuracy in reservoir thickness, net sand and net-pay estimation. Keywords: borehole image, thin bed, sand count, logging while drilling, LWD, SHARP, Net-pay, Water Saturation.